<html>
    <head>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
        <link href="dist/css/bootstrap.css" rel="stylesheet" type="text/css"/>
        <script src="dist/js/bootstrap.js" type="text/javascript"></script>
    </head>
    <body>
        <!-- Small modal -->
        <button type="button" class="btn btn-primary" data-toggle="modal" data-target=".bs-example-modal-sm">Small modal</button>

        <div class="modal fade bs-example-modal-sm" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel" aria-hidden="true">
            <div class="modal-dialog modal-sm">
                <div class="modal-content">
                    <div class="register-title">
                        <h2 class="modal-title">Register</h4>
                    </div>
                    <form role="form">
                        <div class="input-group">
                            <span class="input-group-addon">Username</span>
                            <input type="text" class="form-control" placeholder="Username"/>
                        </div>
                        <div class="alert alert-danger" role="alert">
                            <span class="glyphicon glyphicon-exclamation-sign" aria-hidden="true"></span>
                            <span class="sr-only">Error:</span>
                            Enter username !
                        </div>

                        <div class="input-group">
                            <span class="input-group-addon">Password</span>
                            <input type="text" class="form-control" placeholder="Password"/>
                        </div>
                        <div class="alert alert-danger" role="alert">
                            <span class="glyphicon glyphicon-exclamation-sign" aria-hidden="true"></span>
                            <span class="sr-only">Error:</span>
                            Enter password !
                        </div>

                        <div class="input-group">
                            <span class="input-group-addon">Email</span>
                            <input type="text" class="form-control" placeholder="Email"/>
                        </div>
                        <div class="alert alert-danger" role="alert">
                            <span class="glyphicon glyphicon-exclamation-sign" aria-hidden="true"></span>
                            <span class="sr-only">Error:</span>
                            Enter email !
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </body>
</html>